Re: [Qemu-devel] git bisect results: ec757c67c40a56492001487e69272f62144fd124 breaks windows boot in qemu-kvm

[Erik Rull]

 On February 1, 2012 at 5:01 PM Jan Kiszka <address@hidden> wrote:

> On 2012-02-01 16:43, Erik Rull wrote:
> >  On February 1, 2012 at 3:42 PM Jan Kiszka <address@hidden>
wrote:
> >
> >> On 2012-02-01 15:02, Erik Rull wrote:
> >>>
> >>> On February 1, 2012 at 2:40 PM Avi Kivity <address@hidden> wrote:
> >>>
> >>>> On 02/01/2012 02:52 PM, Erik Rull wrote:
> >>>>>  Hi all,
> >>>>>
> >>>>> first of all I'm a bit confused:
> >>>>>
> >>>>> What is the difference between qemu with command line option
> >>> --enable-kvm
> >>>>> and qemu-kvm?
> >>>>> It seems to be a difference in code so far, from the performance
> > point
> >>> of
> >>>>> view it seems to be the same...
> >>>>
> >>>> The differences are being reduced rapidly, thanks to Jan's efforts.
> >>>> Right now what remains is PIT performance and accuracy, device
> >>>> assignment, and Windows XP performance.  Most guests should see the
> > same
> >>>> performance.
> >>
> >> MSI performance is expected to be worse with upstream as well, thus
> > virtio.
> >>
> >>>>
> >>>>> Now my issue that lead me to a git bisect on qemu-kvm:
> >>>>> The following commit / merge breaks my windows guest boot sequence
> > and
> >>>>> causes resets infinitely:
> >>>>> ec757c67c40a56492001487e69272f62144fd124 Merge branch
> > 'upstream-merge'
> >>> into
> >>>>> next
>
> So commit aad3b517a1b83561f2755dc4451596a421399c19, i.e. the last merge
> before that one is still fine?
>
> >>>>> Thu, 5 Jan 2012 11:00:07 +0000 (13:00 +0200)    Avi Kivity
> >>> <address@hidden>
> >>>>>
> >>>>>
> >>>>> Interesting: qemu with --enable-kvm master and the same command
line
> >>>>> options as qemu-kvm runs perfect.
> >>>>> My command line options are:
> >>>>> qemu-system-x86_64 -serial /dev/ttyS2 -readconfig
> >>> /etc/ich9-ehci-uhci.cfg
> >>>>> -device usb-host,bus=ehci.0 -device usb-tablet -drive
> >>>>> file=/dev/sda2,cache=off -m 1024 -net nic,macaddr=$MACADDR -net
> >>>>> tap,script=/etc/qemu-ifup -no-acpi -monitor stdio -L
> >>> /usr/X11R6/share/qemu
> >>>>> -boot c -localtime
> >>>>>
> >>>>>
> >>>>
> >>>> What version of Windows are you using?  What's the contents of
> >>>> /etc/ich9-ehci-uhci.cfg?
> >>>>
> >>>
> >>> Hi Avi,
> >>>
> >>> the contents from the .cfg are located in docs/ich9-ehci-uhci.cfg
> >>>
> >>> I tried two versions of Windows XP: One is the default Windows XP SP3
> > that
> >>> you get from MSDN, one is Windows Embedded Standard (embedded
> > customized
> >>> XP).
> >>>
> >>> Both show the same behavior: boots with qemu -enable-kvm and
> > continuously
> >>> reboots with qemu-kvm.
> >>
> >> What does qemu-kvm with -no-kvm-irqchip do?
> >>
> >> Jan
> >>
> >
> > Wow - that works!
> > Does this influence the guest performance?
> >
>
> Yes, how much depends on your workload.
>
> Still strange, though. We should try to understand this issue. It stays
> like this up to and including current qemu-kvm.git master?
>
> Jan
>

Hi Jan,

I didn't follow the branch, only the master between 1.0 and head.

Here my bisect log:

git bisect start
# good: [30c044521889195f54a9f2c21310894f545994e8] Merge commit 'v1.0' into
next
git bisect good 30c044521889195f54a9f2c21310894f545994e8
# bad: [2793248c5427c0bc585fdf9c101680bab29f4839] Merge remote-tracking
branch 'upstream' into next
git bisect bad 2793248c5427c0bc585fdf9c101680bab29f4839
# good: [262db38871b9a2613761cc5f05c4cf697e246a68] qemu-nbd: asynchronous
operation
git bisect good 262db38871b9a2613761cc5f05c4cf697e246a68
# good: [9737383beb515a583fdb6f2aafa631fcd6797068] qerror: add
check-qerror.sh to verify alphabetical order
git bisect good 9737383beb515a583fdb6f2aafa631fcd6797068
# skip: [fb5458cd10a199e55e622a906b24f8085d922c0f] qmp: add
query-block-jobs
git bisect skip fb5458cd10a199e55e622a906b24f8085d922c0f
# skip: [aa398a5c3a4c0fc29baf02aee5283a7fa0f202a3] blockdev: make image
streaming safe across hotplug
git bisect skip aa398a5c3a4c0fc29baf02aee5283a7fa0f202a3
# good: [506b7ddf889312659b36c667f7ae17bc9e909418] prep: Use i82378
PCI->ISA bridge for 'prep' machine
git bisect good 506b7ddf889312659b36c667f7ae17bc9e909418
# good: [31841e463fc069f3370f85060fbe450b3ff664b4] Merge remote-tracking
branch 'pmaydell/arm-devs.for-upstream' into staging
git bisect good 31841e463fc069f3370f85060fbe450b3ff664b4
# bad: [5fc4ecdf107133914f97590c8a27144ac0852d63] Merge commit
'5b4448d27d7c6ff6e18a1edc8245cb1db783e37c' into queues/qemu-merge
git bisect bad 5fc4ecdf107133914f97590c8a27144ac0852d63
# bad: [289a1056a2b902e25f8d6ec5e17984aa48d201c1] pci-assign: Fix
multifunction support
git bisect bad 289a1056a2b902e25f8d6ec5e17984aa48d201c1
# good: [7c82a98d17a2e86ce6d933dbdd01a570c7bb4ea8] Merge commit
'03ecd2c80a64d030a22fe67cc7a60f24e17ff211' into upstream-merge
git bisect good 7c82a98d17a2e86ce6d933dbdd01a570c7bb4ea8
# bad: [372951014b5008ca047e4dfbfaf4003bc27a2f6b] qemu-kvm: Fix
save/restore of in-kernel i8259
git bisect bad 372951014b5008ca047e4dfbfaf4003bc27a2f6b
# good: [682a3c07f0e28d2532c911a44a9b6142d6299cc2] Merge commit
'c5705a7728b4a6bc9e4f2d35911adbaf28042b25' into upstream-merge
git bisect good 682a3c07f0e28d2532c911a44a9b6142d6299cc2
# good: [d33666a58d6da4554e69ed6036a052f7261c9298] Merge commit
'c47f3223658119219bbe0b8d09da733d1c06e76f' into upstream-merge
git bisect good d33666a58d6da4554e69ed6036a052f7261c9298
# bad: [ec757c67c40a56492001487e69272f62144fd124] Merge branch
'upstream-merge' into next
git bisect bad ec757c67c40a56492001487e69272f62144fd124


Best regards,

Erik